Filtration apparatus

ABSTRACT

A filtration apparatus which includes a rotating filter, a compressor or blower for providing a positive fluid flow to the rotating filter, and an expander or turbine for extracting energy from the fluid after it has been filtered.

United States Patent I Novak [451 A r. 11 1972 [54] FILTRATION APPARATUS[56] References Cited [72] Inventor: Richard A. Novak, 20 ChestnutStreet, FOREIGN PATENTS OR APPLICATIONS 5mm, Mass- 02108 1,221,6161/1960 France ..2l0/360 [22] Filed: July 13, 1970 Primary Examiner-J. L.DeCesare [21 1 Appl 54507 Attomey-Sewall P. Bronstein and Donald Brown[52] US. Cl ..210/360, 210/380 [57] ABSTRACT A filtration apparatuswhich includes a rotating filter, a com- A; 55/400; pressor or blowerfor providing a positive fluid flow to the rotating filter, and anexpander or turbine for extracting energy from the fluid after it hasbeen filtered.

10 Claims, 5 Drawing Figures PATENTEDAPR 11 912 3,655,058

I INVENTOR RICHARD A. NOVAK BY 0 Y7 AT fi NEYS PATENTEDAPR 11 972 SHEET2 OF 2 lNVE-NTOR RICHARD A. NOVAK BY v ' ATTORNEYS FILTRATION APPARATUSThis invention relates to an apparatus for removing particulate matterfrom a fluid, be it a liquid or gas. The particulate matter can be solidparticles; in a case of a gaseous fluid, particles can be solid orliquid, as for example oil.

Over the years many types of automatic filtration apparatus have beendeveloped for removing particulate matter from fluids. The types offilters and filtration apparatus have included static filters, that isthose where a filter material is provided in the path of the fluid to becleaned and in which the fluid medium is passed therethrough. Inaddition, devices such as scrubbers and centrifuge type devices relyingon the centrifuge principle have also found wide acceptance. In all ofthese devices the cost of operation, ease of maintainance and efficiencyare all important considerations.

The present invention basically relies upon centrifugal motion andincludes means to provide a positive and controlled fluid flow throughthe filtering medium of the device.

The fluid to be passed through the filtering medium is initiallyimparted with a high component of circumferential velocity so that thefluid is first whirled or swirled to remove large heavy particles fromthe fluid prior to the remainder of the fluid carrying other smaller orlighter particles impinging upon the filtering medium. 1

In addition, the efficiency of the filtration apparatus of thisinvention is significantly improved by the use of a turbine or dischargevane system which is adapted to recover the energy (predominatelyrotational) remaining in the moving fluid as it is being discharged fromthe filtration apparatus.

The filtration apparatus of this invention also includes a number ofelements or deflecting devices to control the pressure drop within thesystem and the flow of the fluid through the system so as to maximizethe efficiency of the filtration apparatus.

In view of the above it is an object of this present invention toprovide a new and improved filtration apparatus that not only providedhigh efiiciency but which is also relatively maintainance free.

A further object of this invention is to provide a new and improvedfiltration apparatus which is adapted to remove particulate matter fromeither a liquid or a gas and which includes means for extracting energyremaining in the filtered media.

A further object of this invention is to provide a new and improvedfiltration apparatus which is particularly adaptable for removing oiland other contaminants found in air in a highly efficient manner.

Further objects and advantages of the invention will in part be obviousand will in part be apparent from the specification.

The invention accordingly comprises the features of construction,combinations of elements and arrangement of parts will be exemplified inthe constructions hereinafter set forth.

' The scope of the invention will be indicated in the claims. For

a fuller understanding of the character and the objects of the inventionreference is had to the following description taken in connection withthe accompanying drawings in which:

FIG. 1 is a side elevational view partially in cross section of thefiltration apparatus constructed in accordance with the invention;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a side view showing a tab or vane extension forintroducing,varying and controlling the pre-swirl afiect to the fluid;

FIG. 4 is a sectional view taken along lines 4-4 of FIG. 1;

FIG. 5 is a cross section of a fragmentary portion of a modification ofthis invention.

Reference should now be had to FIGS. 1 through 4 for a description ofthe preferred embodiment of the invention. This apparatus shown in FIGS.1 to 4 is particularly adapted to the filtration of particle ladened gasas for example, gas ladened with dirt, e.g., metal particles or oil,etc.

The device shown in FIGS. 1 through 4 is adapted (though not limited) tobe hung from a ceiling over a machine tool or the like. It is describedas though for shaft vertical installation, it could as well be shafthorizontal. It is adapted, when positioned in this manner, to cleansethe air in the vicinity of the machine too]. As is well known manymachine tools utilize cooling oil or other liquids in perfonning theirfunction. Accordingly, it is highly desirable that means be provided toremove oil particles from the air to avoid machine shop pollution.Similarly, in printing establishments a mist of ink is sprayed into theatmosphere. This becomes toxic in heavy concentrations, and must beremoved.

The apparatus of this invention is also adapted to many other uses, asfor example inthe removal of grease in kitchens, and fibre glass dustfrom factory environments and other places where air is required to befiltered.

The particle or oil ladened air is permitted to enter into thefiltration apparatus through an inlet shown at 10 and which is shown ashaving a bell shaped bottom. In many applications of the device, theparticle or oil laden air will be drawn from ducts which collect the airin hoods adjacent to where the prevention occurs. The inlet 10 iscoupled to a housing 11 preferably cylindrically shaped and having oneor more outlet ports shown at 12 positioned about the top thereof. Thehousing is essentially a pressure tight stationary housing except forthe inlet and outlets therefrom.

In order to drive the rotating elements of the apparatus, there isprovided an electric motor or other drive means 13 which is coupled to adrive shaft 14. The drive shaft 14 rotates in bearing 14a and issupported by bearing 14b. The bearing 14b is supported by members 14ccoupled to the member 10.

Coupled to and journaled to the shaft 14 for motion therewith is a plate15 on which there is mounted a cylindrical member 16 preferably in theshape of a cone and preferably of solid material. The cone 16essentially has its outer wall positioned so as to deflect the fluidmedium out of the housing after it has been filtered. Also coupled tothe plate and supported thereby is a cylindrical filter 17, whichcomprises a frame shown at 17a for supporting a layer of filter material18 such as polyurethane foam, asbestos fiber or the like and which haspositioned along its outer surface a metallic screen 19 (e.g., a i-inchmesh screen).

In the preferred form of this invention there is provided a rotatingcone 20 supported by the frame 17 and adapted to rotate with the cone1'6 and the frame 17. The inner wall of the cone 20 is adapted todeflect the fluid medium in the housing onto the screen as well as toprovide means for permitting the particles centrifuged or whirled awayfrom the screen 19 to impinge thereon and be deflected downward to thebottom of the housing such that the particles can be expelled throughone or more ports in the bottom of the housing shown at 21.

- In order to force the fluid medium and the particles onto the filterthere is provided a compressor or blower which is adapted to feed fluidinto the region between the inner wall of the cone 20 and the filterscreen 19 at a pressure higher than the pressure of the fluid being fedinto the inlet 10 of the apparatus. The compressor comprises a pluralityof fins (see FIG. 2) shown at 23 which are coupled, e.g. by bolts, tothe plate 15 and are adapted to rotate therewith. In the most preferredform, the blades or vanes 23 are provided with tabs or vane extensionsshown at 24 (see FIG. 3) which are coupled thereto and which extendbelow the surface of the bottom portion of the vane 23.

These bent or twisted tabs or vane extensions introduce additionalpre-swirl or counter-swirl of the fluid medium relative to the rotatingfilter screen 19 as well as relative to the filter material 18. Theswirling of the fluid medium aids in the separation of particles bycentrifugal force prior to the particle ladened fluid (e.g. air and oil)impinging on the filter material 18. The adjustable tabs or vaneextensions also provide control of the angle of attack" of the fluidwith respect to the interstices of the filtration media. After the airpasses through the filter screen 19 and the filter material 18, it isdeflected upwardly into an expander or turbine 25 comprising a pluralityof fins or vanes 25a coupled to the topmost portion of the cone'16.

In addition, coupled to the expander 25, there is provided a cylindricaldeflector 26 for deflecting air out of the housing through the outlet12. In the topmost portion of the housing there is provided a sealingmember 27 having a center opening but connected to the side wall of thehousing for preventing air from bypassing the screen and flowing out ofthe outlet 12.

In operation, air is permitted to pass into the apparatus as shown bythe arrow at the inlet and enters the radial compressor comprising vanes23 and van extensions 24. At the discharge of the compressor or blowerthe air passes into the rotating volume 30.

The compressor element which is shown as being predominately radial canalso be an axial compressor or mixed flow compressor as long as itimparts a high component of circumferential velocity to the body offluid (air); the circumferential component of velocity of the air isretained in the volume between the rotating cone and the rotating filtercomprising the screen 18 and the filter material 17.

The compressor therefore serves two functions, it provides the positiveair flow through the device as a whole, pulling polluted air from theatmosphere or from the source of pollution and it also whirls the air ata high circumferential velocity and thereby constitutes a centrifuge. Asthe result of the centrifugal action, all particles which have a masslarge enough so that the centrifugal force exceeds the radially inwarddrag force on the particle are thrown out against the inner surface ofthe rotating cone 20. If the rotating cone 20 is not present, as isshown in the embodiment of FIG. 5 the material is thrown up against theinner wall of the housing. The particulate matter is then centrifugedoutwardly and thereafter falls downwardly to the bottom of the apparatusand is collected through the port 21.

Air, still containing particles of small size, continues through thevolume and onto the rotating filter screen 19 and filter material 18.Depending upon the system pressure drop (and therefore power input intothe system delivered by motor 9 which is allowable) the filter can bemade nearly an absolute filter for any desired minimum particle size. Ifthe particles are a liquid such as oil, they will be slowed in theirpassage through the filter and will agglomerate to a larger size. Theincreased mass of the larger sized particle agglomerates will becomesubject to the centrifugal force field and thrown outwardly and becollected in the same manner as the other particles.

The cleaned air passes into volume 31 and thence into the dischargevanes 25 comprising the expander or turbine. The discharge vane systemis in reality a turbine; it should be understood that it can be anaxial, radial inflow or a mixed flow type of turbine. The dischargeradius and angle or the discharge vane system controls the overallenergy imparted to the system.

In addition, the discharge vane system controls the flow rate of thefluid medium through the filter and the discharge passage 12constitutes, as shown, a radial diffuser designed to recover thevelocity energy (predominately rotational) left in the gas or fluidstream.

This recovered energy is utilized in the system to aid in driving therotating components.

Reference should now be had to FIG. 5 which shown yet another slightlydifferent embodiment of the invention. In this figure like numbers areused for like parts where possible.

In this construction, two filters rather than one are used. They arepreferably in parallel. Thus, for a given fluid total quantity flowthrough the system, the double filter arrangement provides for a largerfilter area, and hence a lower filter pressure drop. Conversely, thelower filter area could be used to accomodate larger quantity flows offluid at the same pressure drop.

In this construction, two cylindrical filters, one within the other, areutilized for filtering the fluid medium fed into the apparatus. Thefilters are shown at and 41 respectively. These filters are adapted tomove together to rotate with the drive shaft 14.

In this configuration, the cone 20 has been removed from the outer wallof the housing 11 and is utilized in place of the inner deflecting wallof the cone 20. In addition, rotating guide means mounted on member 41is provided at 42 for directing the flow of cleansed air out of theoutlet 12. The member 42 is positioned above the expander vanes 25a andis connected to the top of the vanes. In this configuration, there isalso provided pump 45, a reservoir 46 and a suitable piping 47 fordirecting fluid, (e.g. water) against the fluid (gas) being fed into theapparatus. In this manner it is also possible to remove (wash out)particles carried in the gas (air). Thus, the device becomes a scrubberas well as a dynamic filter.

It is to be understood that the pump 45, the reservoir 46 and the piping47 can be removed and the filtration system would then operate in thesame manner as described with reference to FIGS. 1 through 4. It shouldalso be understood that the inner screen (17, 18,19) and cone (31) couldbe removed and the device would function as in FIGS. l-4 but would alsoprovide for scrubbing of the air. It should be observed that FIG. 5 hasa radial inflow expander while FIG. 1 illustrates an axial expander.

It will thus be seen that the objects set forth above among those madeapparent from the preceding description are efficiently attained sincecertain charges may be made in the above constructions without departingfrom the spirit and the scope of the invention. It is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense. It is also to be understood that the following claims areintended to cover all generic and specific features of the inventionherein described and all statements of the scope of the invention whichas a matter of language might be said to fall therebetween.

I claim:

1. An apparatus for removing particulate matter from a fluid comprisinga stationary housing, a rotatable cylindrical filter mounted on bearingswithin said housing, means for driving the filter, inlet means forproviding fluid into the housing, compressor means positioned within thehousing and between the inlet means and the rotatable filter and adaptedto rotate with said filter to produce a positive flow of fluid into saidhousing between the inner wall of said housing and said filter,stationary outlet passage means extending from interior of the housingto the outside of said housing for permitting the fluid to leave saidhousing and turbine means positioned within the housing and between thefilter and the stationary outlet passage means extending into thehousing and adapted to rotate with said filter to extract excess energyof the filtered fluid after it has passed through the filter as well asto control the flow rate of the fluid medium and the pressure drop inthe apparatus, said turbine discharging fluid into the stationary outletpassage means at a point interior of the housing, said compressor meansand said turbine means comprising a plurality of vanes positioned abouta shaft for rotating the vanes and the filter, the outlet passage meansbeing located above the inlet means and the turbine vanes being locatedabove the compressor vanes, the turbine vanes spaced inwardly asubstantial distance from the outer periphery of the compressor vanes,and in which the turbine vanes are positioned below the outlet passagemeans.

2. An apparatus according to claim 1 in which means are provided as partof the compressor for introducing a controlled preswirl or counter-swirlinto the fluid medium and particulate matter before it enters into theregion of space between the inner wall of the housing and the filter.

3. An apparatus according to claim 1 in which a cone is positionedwithin the housing and is adapted to rotate with the filter, the outercone wall providing means for deflecting fluid passing through saidfilter into said turbine means.

4. An apparatus according to claim 3 including a second cone adapted torotate with said filter, said second cone positioned between the innerwall of the housing and the side of the filter positioned to firstreceive the fluid medium containing the particulate matter, said secondcone having an inner wall positioned to deflect fluid medium into thefilter.

5. An apparatus according to claim 1 in which means are provided forpermitting the particulate matter to be discharged from the rotatablecylindrical filter into the stationary housing and means connected tothe stationary housing to permit the particulate matter to exit from thehousing so that the apparatus is self cleaning.

6. An apparatus for removing particulate matter from a fluid mediumcomprising in combination, a stationary housing, inlet means for thefluid, a shaft supported by the housing, a rotatable cylindricallyshaped filter supported by the shaft and having a screen which isadapted to rotate within the housing, means for rotating the filter,compressor means positioned within the housing and between the inletmeans and the filter for producing a positive first fluid medium flowand fluid medium swirl between the screen and the housing, stationaryoutlet passage means for fluid, expander means positioned within thehousing and between the filter and the stationary outlet passage meansfor extracting energy remaining in the fluid medium after the fluid haspassed through the screen, the compressor means and expander means bothincluding a plurality of vanes arranged about the shaft, the outletpassage being located above the inlet passage and the expander vanesbeing located above the compressor vanes, and the expander vanes spacedinwardly a substantial distance from the outer periphery of thecompressor vanes.

7. An apparatus according to claim 6 in which means are provided forforcing a second fluid flow into said housing to impinge upon the firstfluid medium prior to the first fluid medium passing through saidfilter.

8. An apparatus according to claim 6 in which there is provided a secondcylindrically shaped filter adapted to rotate with said first filter,one of said filters positioned within the other of said filters.

9. An apparatus according to claim 6 including common means for rotatingthe filter, compressor and expander means in unison.

10. An apparatus according to claim 6 in which the fluid enters thepassage after leaving the expander at a point closer to the shaft thanthe point at which it is discharged from the passage thereby forming aradial diffuser to the velocity energy of the fluid.

1. An apparatus for removing particulate matter from a fluid comprisinga stationary housing, a rotatable cylindrical filter mounted on bearingswithin said housing, means for driving the filter, inlet means forproviding fluid into the housing, compressor means positioned within thehousing and between the inlet means and the rotatable filter and adaptedto rotate with said filter to produce a positive flow of fluid into saidhousing between the inner wall of said housing and said filter,stationary outlet passage means extending from interior of the housingto the outside of said housing for permitting the fluid to leave saidhousing and turbine means positioned within the housing and between thefilter and the stationary outlet passage means extending into thehousing and adapted to roTate with said filter to extract excess energyof the filtered fluid after it has passed through the filter as well asto control the flow rate of the fluid medium and the pressure drop inthe apparatus, said turbine discharging fluid into the stationary outletpassage means at a point interior of the housing, said compressor meansand said turbine means comprising a plurality of vanes positioned abouta shaft for rotating the vanes and the filter, the outlet passage meansbeing located above the inlet means and the turbine vanes being locatedabove the compressor vanes, the turbine vanes spaced inwardly asubstantial distance from the outer periphery of the compressor vanes,and in which the turbine vanes are positioned below the outlet passagemeans.
 2. An apparatus according to claim 1 in which means are providedas part of the compressor for introducing a controlled preswirl orcounter-swirl into the fluid medium and particulate matter before itenters into the region of space between the inner wall of the housingand the filter.
 3. An apparatus according to claim 1 in which a cone ispositioned within the housing and is adapted to rotate with the filter,the outer cone wall providing means for deflecting fluid passing throughsaid filter into said turbine means.
 4. An apparatus according to claim3 including a second cone adapted to rotate with said filter, saidsecond cone positioned between the inner wall of the housing and theside of the filter positioned to first receive the fluid mediumcontaining the particulate matter, said second cone having an inner wallpositioned to deflect fluid medium into the filter.
 5. An apparatusaccording to claim 1 in which means are provided for permitting theparticulate matter to be discharged from the rotatable cylindricalfilter into the stationary housing and means connected to the stationaryhousing to permit the particulate matter to exit from the housing sothat the apparatus is self cleaning.
 6. An apparatus for removingparticulate matter from a fluid medium comprising in combination, astationary housing, inlet means for the fluid, a shaft supported by thehousing, a rotatable cylindrically shaped filter supported by the shaftand having a screen which is adapted to rotate within the housing, meansfor rotating the filter, compressor means positioned within the housingand between the inlet means and the filter for producing a positivefirst fluid medium flow and fluid medium swirl between the screen andthe housing, stationary outlet passage means for fluid, expander meanspositioned within the housing and between the filter and the stationaryoutlet passage means for extracting energy remaining in the fluid mediumafter the fluid has passed through the screen, the compressor means andexpander means both including a plurality of vanes arranged about theshaft, the outlet passage being located above the inlet passage and theexpander vanes being located above the compressor vanes, and theexpander vanes spaced inwardly a substantial distance from the outerperiphery of the compressor vanes.
 7. An apparatus according to claim 6in which means are provided for forcing a second fluid flow into saidhousing to impinge upon the first fluid medium prior to the first fluidmedium passing through said filter.
 8. An apparatus according to claim 6in which there is provided a second cylindrically shaped filter adaptedto rotate with said first filter, one of said filters positioned withinthe other of said filters.
 9. An apparatus according to claim 6including common means for rotating the filter, compressor and expandermeans in unison.
 10. An apparatus according to claim 6 in which thefluid enters the passage after leaving the expander at a point closer tothe shaft than the point at which it is discharged from the passagethereby forming a radial diffuser to the velocity energy of the fluid.